Utilization of Iron Ore Mines Waste as Civil Construction Material through Geopolymer Reactions

Abstract

In India, due to fast pace development there is a drastic growth in the iron and steel industry. As of 2017, India is one of the largest producers of crude steel in the world. This has led to drastic increase in mining activity. Mining activity is responsible for generation of wastes, which can pose threat to the environment and its habitants. However, there is also a great potential for mines wastes to be utilized in construction industry, which can become an important ingredient for sustainable and eco-friendly development. In iron and steel industry, Iron ore tailings (IOT) and slimes utilization is still an area of challenge, because of the low content of iron oxide present in them, which is unsuitable for metal extraction. Usually particle size of slimes below 1 mm is not amenable for further metal extraction through conventional pelletization techniques. In the present study waste from two different iron ore mines have been tried for their utilization as a construction material through geopolymerisation technology. As a primary consideration, shapes made in the form of common bricks were tested for their densification behavior, compressive strength and water absorption. To reduce the cost, industrial wastes like fly ash, ground granulated blast furnace slag, and lime were tried in different batch compositions in addition to sodium silicate and sodium hydroxide. Relationship between compressive strength values with individual ratio of silica to alumina (Si/Al), silica to alumina with iron combined (Si/Al + Fe), and calcium to silica (Ca/Si) were developed. Based on the elemental ratios, critical threshold values were established that showed significant effect on the compressive strength of the final composite.

The possibility of using waste materials as raw materials for the production of geopolymers

“…It has been observed that the increase in iron ore waste worsens the compressive strength. The best strength values were obtained for 20% IOT, 15% GGBS, 15% fly ash, and 40% slag sand samples [24].…”

“…The large development of this country causes an increase in the steel and iron industry, which is also associated with an increase in the production of waste from this extraction. Research was conducted on the use of iron ore waste from two different mines to produce geopolymer materials [24].…”

“…The resulting paste was made of 230x115x75 mm brick. It was observed that at increased iron ore content, compressive strength increased [24]. A second mix was prepared with iron ore waste, fly ash, slag sand (admixed with blast furnace slag and other aluminosilicate compounds from Jindal Steel LTD., Karnataka in India), blast furnace slag and sodium silicate solution.…”

“…A set of high temperature properties of marked materials in which the composition includes gangue with slag and lime dependence -60. 24 MPa, or gangue with 40.18 slag alone. The lowest available number of samples from the last group of commonly discussed and nominated sludge, gangue, fly ash -7.3 MPa.…”

Iron Ore Tailings as Partial Replacement for Fine Aggregate in Concrete Production – Review

“…According to the study by [32], the XRD pattern of IOT as shown in Fig 3 shows that there is a presence of kaolinite and calcite in addition to the crystalline phase of hematite. Table II: Chemical Composition of IOT…”